Frame the truss, predict every beam's stress, and trust it to carry the weight.
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How to play
Connect nodes with beams to span the gap while staying within budget. Before testing, tag each member as being in tension or compression, then drop the load and watch whether your bridge, and your predictions, stand up.
Click two nodes to add a beam; click a beam to remove it
Build a stable truss without overspending your budget
Tag each member's predicted stress: tension, compression or none
Run the load test and score on a holding bridge plus correct calls
Game modes
Short or Medium spans for difficulty
Daily puzzle or Practice for fresh layouts
Controls
Desktop: click nodes to add beams and click beams to remove them or cycle their predicted stress
Phone & tablet: tap nodes and beams the same way
Tips & strategy
Triangles are rigid, triangulate rather than building long, floppy spans
Top chords usually compress and bottom chords usually stretch under a downward load
Spend on the members carrying the most force; trim beams that do nothing
What you'll learn
Span is a truss-bridge engineering puzzle about how structures carry load, where every beam choice trades strength against a budget.
Skills: structural engineering, forces in trusses, tension and compression, design under constraints
Best for: roughly grades 6–12 (ages 11+)
For parents & teachers: engineering trade-offs made tangible through building and testing.
Origins
Connecting nodes with beams to cross a gap on a budget is truss design, and tagging each member as tension or compression before loading is the original demand.
You commit to the analysis, then watch the bridge decide.
Which members pull and which push is the whole of statics, and it is not obvious from the shape. A beam in tension can be thin and cheap; the same member in compression can buckle and must be stout — so the tags are not a quiz, they are the thing that determines what the structure should be made of.
About Span
Span is a truss-bridge engineering puzzle about structures, stress and budgets. It's an original, free browser game built in-house for PlayPendium.
A free, original browser game on PlayPendium. No download, no install.
